"God himself was once a man as we are now, and is an exalted man, and sits enthroned on yonder heavens!… I am going to tell you how God came to be God. We have imagined and supposed that God was God from all eternity. I will refute that idea, and take away the veil, so that you may see… It is the first principle of the Gospel to know for a certainty the character of God, and to know that we may converse with him as one man converses with another, and that he was once a man like us; yea that God himself, the Father of us all, dwelt on an earth, the same as Jesus Christ himself did; and I will show it from the Bible."

Teachings of the Prophet Joseph Smith
by Joseph Fielding Smith, p345-346